Eraser



Aug. 17, 1954 Filed Oct. 22, 1951 l atentecl Aug. 17, 1954 UNITED STATESPATENT OFFICE ERASER Paul C. Hutton, Charlottesville, Va.

Application October 22, 1951, Serial No. 252,449

9 Claims. 1

My present invention relates to erasers, and has particular reference toan eraser comprising an erasing element composed of a bundle ofrelatively stiff, abrasive filaments such as wire of fine denier, spunglass or the like. While the novel eraser of my present invention isparticularly adapted for use as the erasing or abrading element of apneumatically driven erasing machine, it is to be understood that itsuse is not so limited, and that this eraser is capable of use with powerdriven erasers of any desired or preferred construction, and that thiseraser may also be used as a hand actuated or operated eraser.

It is an object of my present invention to provide an eraser composed ofa bundle of relatively stiff abrasive filaments, and to provide a novelholder for such filaments which will function as a means for enclosingand retaining the bundle of filaments and for projecting one end of saidbundle beyond the end of the holder to constitute the erasing surface.

It is a further object of my present invention to provide an erasercomposed of a bundle of relatively stiff abrasive filaments, and toprovide a novel holder for such filaments which will function as a meansfor enclosing and retaining the bundle of filaments and for rojectingone end of said bundle beyond the end of the holder to constitute anerasing surface of annular configuration.

It is a further object of my present invention to provide a novel holderfor a bundle of relatively stiff abrasive filaments, which holderpreferably has an outwardly-flared or frusto-conical end portion withinwhich is positioned a substantially conical spreader member, theconfiguration of the end portion of the holder and of said conicalspreader member serving to spread one end of the bundle of filamentsinto an annular erasing surface which, when moved lightly over thesurface of paper, parchment or the like, will readily erase or removefrom such surface pencil, ink, paint or pigment lines or markingsappearing on the surface of such paper, parchment or the like.

It is a further object of my present invention to provide a novel holderfor a bundle of relatively stiff abrasive filaments, which holderincludes a tubular portion which terminates at one end in anoutwardly-flared or frusto-conical portion, and to provide asubstantially conical spreader member within the said outwardlyfiared orfrusto-conical portion, the bundle of filaments being enclosed andretained within the holder, and means being provided to force saidbundle outwardly of the tubular holder through the outwardly-flared orfrusto-conical end portion thereof and beyond the conical spreadermember, whereby the bundle of filaments is spread outwardly to form anannular erasing surface of a diameter exceeding that of the unspreadbundle of filaments, the arrangement being such that the end of saiderasing surface is disposed at an angle such as to be substantiallyparallel to the surface to be erased when the said holder is disposed atan angle to such surface.

It is a still further object of my present invention to provide aneraser holder of the above referred to character which includes a novelmeans for mounting and retaining the conical spreader member within theoutwardly-flared or frusto-conical end of the holder, and to provide aneraser of the character above referred to which is strong and durable,relatively cheap and easy to manufacture and assemble, and which ishighly efficient in the purposes for which designed.

In the accompanying drawings wherein for the purpose of illustration isshown a preferred embodiment of my present invention:

Figure l is a fragmentary, part elevational and part sectional view ofan eraser holder constructed in accordance with my present invention;

Figure 2 is a view similar to Figure 1 showing the eraser holder turnedninety degrees from the position shown in Figure 1;

Figure 3 is a view similar to Figure 1 showing a bundle of filaments ofwire of fine denier, spun glass, or the like within the holder and withthe lower portion of said bundle spread or flared outwardly andterminating beyond the flared end of the holder to form an annularerasing surface, this view being taken on the line 3-3 of Figure 4;

Figure 4 is an enlarged, transverse sectional view on the line 4-4 ofFigure 3, and

Figure 5 is an exploded view showing, in perspective, the conicalspreader member and the preferred means for retaining the same inposition within the outwardly-flared or frusto-conical end portion ofthe holder.

In the accompanying drawings, wherein like reference numerals have beenemployed to designate like parts throughout the several views, thenumeral I designates a shaft preferably of circular transverse crosssection. This shaft I may be of a diameter approximating that of anaverage size pen-holder or pencil. If the eraser of my present inventionis to be employed as the erasing element of a pneumatically,electrically, or mechanically driven erasing machine, the shaft I issuitably connected to the driving mechanism of such machine in a mannersuch as to be rotated about its axis, preferably at a relatively highspeed, as is customary in the operation of such machines.

The improved and novel eraser holder of my present invention comprises atubular element 2 of an internal diameter such as to tightly engage theend portion of the shaft I when said shaft is slidably engaged withinsaid tubular element. By virtue of the relatively tight fit existingbetween the inner surface or bore of tubular element 2 and the outersurface of shaft 2, the said tubular element 2 is frictionally retainedon the shaft i and is caused to rotate therewith. While the tight fitexisting between the shaft l and the tubular element 2 is such as toconstrain these two members for simultaneous rotation, it is possible,upon the exertion of a reasonable amount of manual force, to slide theelement 2 axially oi the shaft 1 for a purpose to be hereinafterdescribed. If desired, the external configuration of the shaft l and theinternal confiuration oi the bore of the tubular element 2 may be ofsquare, rectangular, or of other noncircular form in transverse crosssection, whereby rotation of the shaft will positively effectsimultaneous rotation of the tubular element 2 without the possibilityof slippage. In other words, the engagement between the shaft 1 and thetubular element 2 may take any desired or preferred form, it merelybeing necessary that the engagement be such as to insure simultaneousrotation of the two parts while permitting axial movement of one partwith respect to the other.

The tubular element 2 of my present invention includes a cylindricalportion 3 which terminates at one end in an outwardly-flared orfrusto-conical portion 5 having pairs of diametrically-opposite,axially-extending slots 5 and 8 therein, the pair of slots 5 beingsomewhat longer than the pair of slots 6. Preferably the planecoinciding with slots 5 is at right angles to the plane coinciding withslots 6, as best shown in Fig. i of the accompanying drawings.

A spreader member I is secured within the outwardly-flared orirusto-conical portion 4 of the holder, and comprises a conical member 8having pairs of diametrically-opposite, axiallyextending slots ii andill therein, the pairs of slots 53 being somewhat longer than the pairof slots id as best shown in Figure 5 of the accompanying drawings. Thelengths and angular dispositions of the slots ii and i8 correspond tothe lengths and angular dispositions: of slots 5 and 8, respectively. Itis to be particularly noted that the sides of the conical spreadermember I are formed at a greater angle to the longitudinal axis of thetubular element 2 than are the sides the outwardly-flared orfrusto-conioal portion l of tubular element 2. When the conical spreadermember I is disposed within the portion i, the outer surface of saidspreader member is disposed and maintained in spaced relation withrespect to the inner surface of portion the spacing between the upper orapex portion of said spreader and the adjacent inner wall of portion lbeing greater than that between the lower portion or base of saidconical spreader member and the adjacent inner surface of portion i, allas clearly shown in Figures 1, 2 and 3 of the accompanying drawings.Preferably, the total area of the annular space between the lowerportion or base of the conical spreader member 3 and the lower end ofthe outwardlyfiared or irusto-conical portion i is substantial- 1y equalto the area of the bore of cylindrical portion of tubular element 2, fora purpose to be hereinafter described.

As a means for rigidly securing the conical spreader member 1 within theoutwardly-flared or frusto-conical portion l of the holder, I providetwo relatively thin, fiat joining strips l l and I2, the upper edges ofwhich strips are sharpened or bevelled as indicated at l3 and Mt. Stripi i is provided at its opposite, upper corners with 4. bendable tabs orprojections 15 and H3 beneath which are outwardly and downwardlyinclined end walls '5 and 18 each formed on an angle corresponding tothe angle of the outer surface of frusto-conical portion l of theholder. The end walls of strip ll terminate at their lower portions ininwardly and downwardly inclined wall portions 9 and 20. Strip- 12 isprovided with an open-ended vertical slot 23 which extends upwardly fromthe lower edge of said strip toward the top edge thereof at about themidportion of said strip, the length of this slot corresponding to theheight of the strip H and being of a width slightly less than thethickness of said strip H, the strips H and [2 each being of a thicknessslightly greater than the width of the slots 5 and E in theoutwardly-flared or trusts-conical portion 4 of the holder 2, and of athickness slightly greater than the width of the slots 3 and it in theconical spreader member l. The end walls 22 and 23 of strip iii in clinedownwardly at an angle corresponding to the angle of the portion a ofthe holder 2, these end walls terminating in inwardly and downwardlyinclined portions 25 and 25.

Having thus described the construction of a preferred form of filamentholder forming part of my present invention, I will now describe themanner of assembling and using the same. The first step of assemblyconsists in forcing or tapping the strip H into the slot 2| in strip i2so that the strip H is firmly and securely held within the said slotwith the said strips forming a cruciform structure. The cruciformstructure thus formed is then forced or tapped into the slots 5: and it!of the conical spreader member '5, strip i2 entering slots 5 and stripii entering slots it, the outer end portions of said strips projectingoutwardly an appreciable distance beyond the outer surface of saidconical member l. The conical member 1 and strips ii and i2, assembledas described, are now moved to a position within the outwardly-flared orfrustoconical portion 4 of the holder, the end portions of strip i2 areforced or tapped into slots 5, and the end portions of strip H areforced or tapped into slots 6 with the tabs or projections l5 and itprojecting outwardly beyond the outer surface of portion i of the holder2. rhe tabs or projecting portions 45 and it are then bent at rightangles to the plane of strip ii and thus overlie and engage the outersurface of the portion 5. Since these tabs or projections I5 and N5 arepositioned intermediate the length of the inclined outer surface ofportion =3, they effectively prevent the strips H and i2 and the conicalspreader member I, to which they are rigidly secured, from movingoutwardly of the holder. This assembly operation positions the conicalspreader member 1 within the holder with the apex of said member locatedon the axis of the tubular portion 3 of the holder, and with the outersurface of the said spreader member maintained in proper spaced relationwith respect to the inner surface of portion l, all as clearly shown inthe accompanying drawings.

A cylindrical bundle 2%. of wire of fine denier, spun glass or likestraight and relatively stifi abrasive filaments is then insertedaxially into the bore of tubular portion 3 of the holder through theupper, open end thereof. The holder with the filaments therein is thenplaced over the end of shaft 2 and is moved axially of said shaft.During this relative axial movement, the end of the shaft I within theholder acts as a piston or ram to force the lower end of the bundle offilaments against the apex of the conical spreader member I and throughthe downwardly converging space between the outer surface of the saidmember 1 and the inner surface of portion 4 of the holder. This relativeaxial movement between the holder and shaft is continued until the endsof the filaments project beyond the end of the holder and thus form aneraser of annular configuration with the outermost edge or bottomsurface of such eraser inclined at an angle which will enable said edgeor bottom surface to be substantially parallel to the surface to beerased. when the shaft and holder are inclined with respect to thesurface to be erased, i. e., when the shaft, holder and eraser are heldat an inclination corresponding substantially to that at which a pen orpencil is usually held when writing on a fiat surface. It is to be notedthat when the bundle of filaments 26 is being moved axially toward theoutwardly-flared or frusto-conical end portion 6, the lower end of saidbundle is forced into contact with the tip or apex of the conicalspreader member l. Continued downward movement of the bundle it movesthe lower end of the said bundle along the downwardly converging annularspace between the outer surface of the spreader member 7 and the innersurface of portion 4. During such downward movement, the descending andoutwardly-flared lower end of bundle 26 will contact the upper sharpenedor bevelled edges :3 and M of strips H and [2, respectively, suchcontact serving to divide the said lower portion of the bundle into foursubstantially equal parts. Obviously, this division of the bundle andthe engagement of appreciable lengths of the filaments with the sides ofthe members i i and i2, will serve to prevent axial rotation of the saidbundle within the holder, and will eifect axial rotation of the bundleof filaments simultaneously with axial rotation of said holder whenshaft I is rotated. Due to the fact that the area of the annular spacebetween the base of conical spreader l and the base of theoutwardly-flared or frusto-conical portion 4 is substantially equal tothe cross sectional area of tubular portion 3 of the holder and thecross sectional area of bundle 26 contained therein, the filaments whichproject from the lower end of the holder 2 are maintained in closelyarranged and relatively stiff relationship and thus form an effectiveannular erasing surface. The larger area provided by the space betweenthe apex of the conical spreader member "I and the upper end offrusto-conical portion i is very desirable, because the relatively stififilaments 26 must bend as they pass down between the spreader member land the frusto-conical portion 4, and this bending causes a certainamount of separation of the filaments. Also, the larger area justmentioned is desirable to reduce the friction offered to longitudinalmovement of the filaments by thrust from the piston or ram provided bythe end of shaft 1.

When the device of my present invention is rotated by a pneumatically,electrically, or mechanically operated machine, the shaft l is rotatedby such machine, which rotation is effective in driving the holder andthe abrasive erasing filaments disposed therein. The holder ispreferably held at an angle to the surface being erased so that thelower, annular, projecting edge of the abrasive filaments, where suchedge contacts said surface is substantially paral- 6. lel to the surfacebeing erased. When the olevice of my present invention is used as asimple, manually-operated eraser, the holder is inclined with respect tothe plane of the surface to be erased and is held between the thumb andfingers of the operator much in the same manher as an operator wouldhold a pen or pencil, a slight reciprocating, oscillating, or circularmovement being imparted to the holder, with a portion of the annular endof the filaments in contact with the matter to be erased from the paper,parchment, or like surface to effect the desired erasing operation.Obviously, when continued abrasion wears away the projecting ends of thefilaments, the eraser may be restored to its initial efficiency bythrusting shaft 1 against the upper end of the bundle of filaments tocause the lower ends of the filaments to protrude the desired amountfrom the lower end of the filament holder. This operation may b repeatedas the eraser is used and until the filaments are so shortened byabrasion that they will not be displaced longitudinally, at which timethe inner end of shaft 1 is in contact, or nearly in contact, with theapex of cone 8. When the filaments have been used up, a refillconsisting of a new bundle of filaments may be readily inserted in theholder for future use.

It is to be understood that the form of my invention herein shown anddescribed is to be taken as a preferred embodiment of my invention, andthat various changes may be made in the shape, size, and arrangement ofparts without departing from the spirit of my invention or from thescope of the subjoined claims.

Having thus described my invention, I claim:

1. An eraser holder comprising a hollow member, a spreader member withinone end portion of said hollow member with the outer surface of saidspreader member spaced inwardly from the inner surface of said one endportion, a first strip extending across said one end portion and securedthereto, and a second strip extending across said one end portion andsecured thereto, said spreader member engaging said strips and beingretained within said one end portion of said hollow member by saidstrips.

2. An eraser holder comprising a hollow mem-- bar, a spreader memberwithin one end portion of said hollow member with the outer surface ofsaid spreader member spaced inwardly from the inner surface of said oneend portion, a first strip extending across said one end portion andsecured thereto, and a second strip extending across said one endportion and secured thereto, said strips each having a sharpened upperedge directed toward that end of said hollow member opposite said oneend portion, said spreader member engaging said strips and beingretained within said one end portion of said hcllow member by saidstrips.

3. An eraser holder comprising a hollow member having a pair of spacedslots through one end portion thereof, a spreader member within said oneend portion of said hollow member with the outer surface of saidspreader member spaced inwardly from the inner surface of said one endportion, said spreader member having a pair of spaced slotstherethrough, and a strip extending across said one end portion of saidhollow mem-- her with the ends of said strip secured within the slots insaid one end portion, said strip being secured within the slots in saidspreader member for retaining said spreader member within said, one. endportion of said'hollow member.v

4. An eraser holder as defined in claim 3, wherein the pair of slots insaid one end portion of said hollow member are alined with the pair ofslots in said spreader member, and in which the strip is a straightstrip secured within said pairs of alined slots.

5. An eraser holder comprising a hollow member having a frusto-conicalend portion having circumferentially-spaced pairs of slots extendingtherethrough, a conical spreader member within said end portion andhaving its outer conical surface spaced inwardly from the inner surfaceof said frusto-conical end portion with the bases of said end portionand conical spreader member in substantially coplanar relation, saidconical spreader member having circumferentiallyspaced pairs of slotsextending therethrough, a first strip extending across said one endportion and secured within one of the pairs of slots in said end portionand one of the pairs of slots in said conical spreader member, and asecond strip extending across said one end portion and secured withinthe other pair of slots in said end portion and the other pair of slotsin said conical spreader, said strips retaining said spreader memberwithin said end portion of said hollow member.

6. An eraser comprising a hollow member, a spreader member within oneend portion of said hollow member with the outer surface of saidspreader member spaced inwardly from the inner surface of said one endportion, means secured to said one end portion and extending across thespace between said spreader member and said end portion and engage bysaid spreader member to retain the same within said one end portion ofsaid hollow member, a bundle of abrasive filaments within said hollowmember, and means for forcing said bundle of filaments through saidhollow member into contact with and beyond the spreader member to aposition where an end of said bundle of filaments projects outwardlybeyond said one end of said hollow member.

'7. An eraser comprising a tubular member having a frusto-conical endportion, a conical spreader member within said end portion of saidtubular member with its outer conical surface spaced inwardly from theinner surface of said irusto-conical end portion, means secured to saidend portion and extending across the space be tween said conicalspreader member and said end portion and engaged by said spreader memberto retain the same within said end portion of said tubular member, abundle of abrasive filaments within said tubular member, and a shaftextending into said tubular member from the end thereof opposite saidfrusto-conical end portion, said shaft fitting within the bore of saidspread member within said end portion of said tubular member with arelatively tight frictional fit, and said shaft and tubular member beingaxially slidable with respect to each other whereby the end of saidshaft within said tubular member will engage the end of the bundle offilaments and will force the same through the tubular member intocontact with and beyond the spreader member to a position where an endof said bundle of filaments projects outwardly beyond said end portionof said tubular member.

8. An eraser comprising a shaft having a. solid lower end providin apiston or ram, a hollow tubular member fitting over the lower end ofsaid shaft and extendin axially beyond said lower end of said shaft,said tubular member being movable longitudinally relative to said shaft,a. bundle of stiff abrasive filaments within the interior of said hollowtubular member and having its upper end abutted by said solid lower endof said shaft and having its lower end projecting from the lower end ofthe tubular memher, said lower end of said tubular member beinfrusto-conical, a conical spreader member wholly enclosed by and havingits outer surface spaced inwardly from the inner surface of said lowerfrusto-conical end of the tubular memher, and means extending across thespace between said conical spreader member and said frusto-conical endof the tubular member for securing the conical spreader member to thelower frusto-conical end of the tubular member, said means permittingthe filaments to move endwise past it and acting to hold the bundle offilaments against rotation with respect to said conical spreader memberand said frusto-conical end of the tubular member when the shaft andtubular member are rotated about their common axis.

9. An eraser comprisin a shaft having a solid lower end providing apiston or ram, a hollow tubular member fitting over the lower end of theshaft and extending axially beyond said lower end, said tubular memberbeing movable longitudinally relative to the shaft, a bundle of stiffabrasive filaments within the interior of said hollow tubular member andhaving its upper end abuted by said solid lower end of said shaft andhaving its lower end projecting from the lower end of the tubularmember, said lower end of said tubular member having a frusto-conicalportion, a conical spreader member wholly enclosed by and havin itsouter surface spaced inwardly from the inner surface of said lowerfrustoconical portion of the tubular member, and means securing theconical spreader member to the lower frusto-conical portion of thetubular member, said means extending across the space between theconical spreader and said frustoconical portion and permitting thefilaments to move endwise past it freely and acting to hold the bundleof filaments against rotation with re-- spect to said conical spreadermember and said frusto-conical portion when the shaft and tubular memberare rotated about their common axis, the annular space between the apexof the conical spreader member and the upper end of the frusto-conicalportion of the tubular member being greater than the annular spacebetween the base of the conical spreader member and the lower end of thefrusto-conical portion of the tubular member so that the filaments maybend and separate somewhat as they move past the apex of the conicalspreader member, the area of the annular space between the conical.spreader member and the frusto-conical portion end of the tubular memberbecomin less as the lower ends of the frusto-conical portion and of theconical spreader member are approached and said area at said lower endsbeing substantially equal to the area of the hollow tubular member abovethe frusto-conical lower end and above the apex of the conical spreadermember.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 44=9Jl61 Wolcott Mar. 24, 1891 1,005,924 Baldwin et al. Oct.17, 1911 ,398,823 Fisher Apr. 23, 1946

